- Evolved from the earliest vascular plants, which lacked seeds
- Pterophyta (Ferns)
- Psilophyta (Whisk Ferns)
- Lycophyta (Club Mosses
Pterophyta (Ferns)
- Most abundant group of seedless vascular plants (12,000 species)
- Flourish throughout the world but 75% of species found in the tropics.
- Typically have an underground stem system referred to as a rhizome.
- Feathery dissected leaves refereed to as fronds
- Homosporous, producing distinctive clustered sporangia where meiosis occurs creating spores.
- At maturity spores are catapulted from plant into damp areas where they may germinate.
Psilophyta (Whisk Ferns)
- Another phyla of seedless vascular plants.
- Free water required for process of fertilization in which flagellated sperm unite with egg.
- Simplest of all extant vascular seedless plants.
- Form parasitic associations with fungi
Lycophyta (Club Mosses)
- Crazy little dudes.
- Abundant in tropics and moist temperate regions.
- Superficially resemble "true mosses"
- Either homo- or heterosporous.
- Leafy stemmed sporophytes.
